This invention relates to an improved firing mechanism which is readily adaptable for use on muzzle-loading firearms whether they are of the rifle or pistol type.
During the evolution of firearms a type of firearm was developed which required that the marksman pack his powder charge and ball through the firearm muzzle. To ignite the powder charge an ignition source was provided externally of the interior of the bore of the firearm barrel. In the earliest times this ignition source was provided by the utilization of a matchlock or a flintlock system which caused ignition of a smaller powder charge which, when ignited, communicated a spark or flame through a flash hole to the main powder charge. As technology developed, this type of ignition system was replaced by the utilization of a percussion cap which provided the ignition source through a flash hole when struck by the firearm hammer. The percussion cap had many advantages over the matchlock and flintlock systems in that it was faster to load and was much more resistant to moisture from rain, dew, etc. This resistance to moisture was a direct result of the fact that the charge is held inside of a small metal cannister and thus was somewhat shielded from these elements.
While the percussion cap was a great advancement over the earlier systems, it suffered drawbacks which were peculiar to its own nature and still did not overcome other drawbacks which are peculiar to the utilization of an ignition source which is exterior to the main charge of the firearm. One drawback which is peculiar to the percussion cap is that it is made of a fragile material which can, on occasion, break apart and become a miniature missile as the main charge ignites. As can be appreciated, this presents a safety problem as such fragments can result in eye injury to the marksman. Since the percussion cap requires utilization of a flash hole it experiences the same drawbacks as the older matchlock and flintlock systems in that there is blow back through the flash hole when the main powder charge ignites. This blow back could be dangerous to the marksman as hot gases and burning powder could be blown back into the marksman's face. This disadvantage was somewhat mitigated by structuring the geometry of the flash hole so that the blow back is directed away from the marksman. One means of reducing the amount of blow back is to make the size of the flash hole relatively small so that only a minimal amount of escaping gas would traverse the flash hole. Doing this, however, also creates problems in that, especially when utilizing black powder, burnt powder deposits form in the flash hole and partially or totally clog it with residue. When this occurs there is a chance of a misfire or a hang fire--misfire being a result of failure of the igniting spark or flame from the percussion cap to ignite the main powder charge and the hang fire being the result of only partial ignition of the main powder charge.
In modern times the utilization of muzzle-loading weapons has met with great popularity as it provides the marksman with a nostalgic trip into the past and a challenge of his marksmanship ability. Since the above-discussed disadvantages realized by using a percussion cap have no real effect on the challenge presented to the marksman, the mitigation of these disadvantages will only inure to the marksman's safety and not detract from the reason that the marksman would utilize a firearm. This fact has been recognized in the prior art in recent years. See for example, U.S. Pat Nos. 3,780,464, 4,114,303, and 4,222,191. While the ignition mechanisms shown in these patents are alleged to overcome the disadvantages mentioned above when utilizing muzzle-loading weapons, they are complex in structure and inconvenient in use. For example, in U.S Pat. No. 4,114,303 a shot shell primer is utilized which relies upon a fraction-fit in an igniter barrel. It is easy to appreciate that such shot shell primer is subject to falling from the ignition barrel resulting in a misfire.
Therefore it is an object of this invention to provide an ignition system which can utilize conventional caps and primers and which requires structure which is the paragon of simplicity, but which, at the same time, prevents blow back and missiling of caps or primer fragments. Also by the utilization of the system of this invention, the flash hold can be dimensioned somewhat larger than in prior art systems as the blow back problem has been greatly reduced, if not totally eliminated.